Plaster is a porous building material that can be used for a multitude of indoor craft projects, including making decorative plaques and hanging garden stones. The inexpensiveness and malleability of plaster make it suitable for use as a mold for other materials, such as clay, craft dough and concrete. However, the primary ingredient in plaster powder, gypsum rock, is highly malleable and may be dissolved through exposure to wind, heat and rain. For this reason, plaster is not suitable for outdoor construction projects. Your stones would crack or develop mold if used to create a functional pathway. Instead, use plaster to create a purely decorative garden stone.
Cover your workspace with newspaper or a plastic tarp.
Pour the 1 cup of water into the bowl.
Add 2 cups plaster.
Let the plaster absorb the water for 30 to 60 seconds.
Stir the mixture slowly to incorporate the undissolved plaster. Do not lift the stirrer from the bowl, as this will create air bubbles.
Add more plaster or water as needed until the mixture reaches a smooth consistency similar to pancake batter.
Tap the bottom of the bowl from the outside to release any trapped air. Continue tapping until air bubbles stop breaking the surface of the plaster.
Add two to three layers of wire mesh or fabric, such as cotton or denim, to the middle of your mold as you pour the plaster. Do not use a coated fabric as the plaster must penetrate the material.
Add glitter or fine craft sand to texture and decorate your plaster.
Remove any loose, crumbly bits from the damaged areas using a chisel or a wire brush. Widen narrow cracks a bit to accommodate the insertion of the cement.
Add water to the dry cement mix as instructed in the manufacturer's instructions. Waterproof cement typically cures rapidly. Only mix as much as you can use within the curing time indicated in the manufacturer's instructions.
Form a ball of cement in your hands then go underwater and force the cement into the cavities. Push it in firmly to ensure no air or water gets trapped beneath the patch.
Hold a pool trowel at a slight angle and scrape one edge across patched areas to smooth down and level the cement.
Locate the source of the metal that is infecting the pool water. This is paramount to correcting the problem and might require professional service for your system. It will do no good to remove the staining if metal continues to contaminate the pool, because the staining will return.
Fill an old sock with 1/2 lb. of pH reducer. Tie off the open end of the sock to create a bag for the chemical. Drop the sock into the water near the stain.
Grab the sock with the pool pole and push it down until it settles on the stain. You need to leave the sock in place for five to ten minutes. Either prop the pole to hold the sock down or stand holding the pole in position.
Lift the sock off the spot, if it is gone, then treat the next stain with the same sock. If the spot is still visible, repeat the process. Move the sock around the pool until all spots disappear.
One of the first materials to be used for swimming pool construction was plain, white plaster similar to the material used to make body casts. Plaster is relatively inexpensive, making it popular for covering large sections of a swimming pool. If it becomes chipped, plaster can be patched. Plaster is typically a basic white but can be painted.
Stronger than plaster, concrete surfaces for swimming pools are common for large pools that have to withstand a lot of wear, tear and use, such as public pools. Concrete is usually poured into forms that are joined to create the entire pool. The poured concrete is smoothed so that the pool has no runs or rough spots. Concrete can be left bare or it can be painted in a single color or in designs. If the concrete cracks or if the surface becomes pitted or scarred, it can be sanded down and a fresh coat of concrete poured over the top to resurface it.
Fiberglass and vinyl
Another popular resurfacing option is fiberglass, a durable material made of interlocking fibers that often feels like plastic. It can be purchased in cast shapes that fit over a pool's surface; cracks or holes in fiberglass can be repaired with fiberglass patches. Fiberglass is often covered with vinyl surfacing, allowing the pool owner to customize the color, texture and design. Vinyl covering hides any fiberglass patches, and can also be patched if it tears.
Use the stiff brush at least twice a week to scrub the sides and floor of pool. You don't need type of soap on the brush; the brushing action will do the cleaning. This will prevent many things from getting a foothold in your plaster, thereby greatly reducing your need to go into full-blown stain removal mode.
Apply a pile of granular chlorine to any stained spots in the plaster on the floor of a filled pool. This will help bleach any stains out. Use enough to completely cover the stain. Leave it in place until it naturally dissolves and dissipates.
For walls, your pool supply store will have a gel-type bleach specially designed to adhere to walls.
Sand any remaining stains with sandpaper.
Acid wash the pool if none of the above methods work. Drain the pool, scrub the walls with water, then pour a mixture of acid and water at a 50/50 ratio down the walls. Scrub the walls with the acid and rinse thoroughly with a garden hose. This method will remove a thin layer of plaster, leaving you with a new surface to start over with. To prevent future problems, scrub your walls and floor with a brush regularly.
Put on your protective gear. Safety gloves and goggles are necessary for preventing hand irritation and sand flying into your eyes.
Chisel away at the small holes and cracks. The bigger you make the hole, without getting too excessively large, the easier it will be to fill it completely.
Create your plaster mixture of 1/3 Portland cement and 2/3 white sand. You will need to add dye to the mix if your pool is any other color than white.
Combine the mixture with an acrylic bonding agent. The consistency should be that of a thick paste.
Fill the cracks and holes with the mixture using your pool trowel. A pool trowel is a flat metal tool with rounded edges that allows you to smooth over plaster surfaces of the pool.
Fill the pool with water when the patches are dry.
Bevel the area around the crack with the hammer and chisel to 3/8-inch deep. Brush away any lose plaster or debris.
Mix dry pool plaster and water in a bucket. Follow the instructions on the label for how much water to add. Thoroughly mix with a paddle until the mixture becomes a smooth, thick consistency with no lumps.
Put the mixture in the palm of your hand and, with a twisting motion, press firmly down into the crack. Wear a face mask or goggles if you must go underwater to apply the patch. Rub the mixture completely into the crack with your hand.
Push down firmly on the patch with the trowel and then trowel over it to remove excess plaster. Press down on the patch again with the trowel.
Rub the patch with your hand to smooth the edges. Use your fingers to rub off any excess mixture and ensure a smooth edge with the existing plaster.
You've determined a repair patch is necessary in the plaster pool, because you see a spot where loose plaster is no longer bonded to the surface. How fortunate you are: not only will you save yourself a lot of money doing it yourself, but compared to replastering an entire pool, it's a cinch to simply patch a plaster pool.
While it's somewhat tricky to make the transition between the new plaster and the old plaster evenly smooth, and get an exact color match between them, yet even if you tend to repair things as if you have two left hands, this repair job only requires some stick-to-itevness to get it right.